You did ask about the ambient and before closing the discussion you may want to get someone to clarify if 90 ambient is too high.
I am thinking it is and there wouldnt be much ability for the snake to regulate to a cooler temp if it wanted to. This having nothing to do with why it is in the hide most of the time, which is normal.
My snake stays in the hide all day, and at night she just poked her head out and chills. Then about 1 to 2 days before feeding day she starts to roam around at night. After feeding she is hide bound.